Thread Starter


I read a lot of articles about HMI and I never find lonworks. Is there anybody who know a lonworks network controled by an HMI?
What is SCADA? Is it the same thing of HMI?
Thanks to show me web sites if you know them.

Audun Alvestad

HMI means Human Machine Interface. Earlier it was called MMI (Man Machine Interface) but some ladies :) didn't like it so it was renamed.

SCADA is used in the same way
(SupervisingControlAndDataAcquisition ithink)

Lonworks is especially for building automation and have so far had limited support to traditional automation.

But there are now OPC's for Lon and I know that Moeller PLC's have Lon modules. Most HMI systems support OPC. Genesis32 fromIconics recommended. Others PLC should have familier support.

Peter Whalley

Hi Franck,

I understand that Gesytec have a LONTalk driver for Linux that is currently distrubuted under GPL.
See .

You may need to purchase their LONTalk FTT10 interface card but you will probably need something like that in any case.

You might like to consider working on a LONWorks interface to the PuffinPLC ( and publishing your results under GPL. That would be very useful as there is currenly a lack of products which allow a Linux based PLC (or any other soft PLC for that matter) to talk to LONWorks.

Yes HMI and SCADA (Supervisiory Control and Data Aquisition) are generally similar although SCADA may include the actual data communications and field I/O.

Some SCADA HMI packages have direct LONWorks interfaces available from third parties (eg Citect and FIX) but most use DDE as Echelon have a couple of DDE servers that you can use. Alternatively you can use OPC but I have yet to see anyone get this working properly.

Since you're interested in Linux, you may also like to consider developing a LONTalk to ACPLT/KS interface.
See This provides a platform independent open alternative to OPC.

Hope this helps and I look forward to seeing your driver.


Peter Whalley

Managing Director
Magenta Communications Pty Ltd
121 King Street,
Melbourne, VIC 3000

e-mail: [email protected]
Hello franck,

If you have already read some articles about HMI, certainly you know what does it means, Human Machine Interface.
SCADA means Supervisory, Control And Data Acquisition, which are systems used to super visioning and control equipment that are, normally distant from the place where control is made. It's used in Energy Distribution control, Gas, Oil, etc.
Basically, the SCADA systems are equipment with I/O cards, digital and analog, controlled by microprocessed cards that communicates with the
Control Center (when HMI is) by some communication mean with standard or non-standard protocols. Lownworks is one of the possible protocols used to communicate.
Just another thing, HMI is software that runs in a machine, based on Unix, Windows, or other OS, that makes the usage of the system more

I hope that it helps you on understand the basic ideas.

Best regards,